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The Philosophy of Truth

I've spent half a century writing for radio and print (mostly print). I hope to still be tapping the keys as I take my last breath.

How do we know that something is true in philosophy?

How do we know that something is true in philosophy?

Science and the Erasure of Mysteries

Science has taken away many of the mysteries that governed our ancestors’ lives. The scientific method is used to solve puzzles. It works this way:

  • a question is asked;
  • a possible answer is proposed;
  • an experiment is set up to test the answer; and
  • the experiment is repeated many times, and the results are noted.

Over time, it will emerge whether the proposed answer is right or wrong, true or false. However, philosophers view truth differently. For them, exact results to questions can’t be delivered through repeated experiments.

Philosophical Puzzles

One person’s truth might well be another person’s untruth. What is true today might not be true tomorrow. So, how can we know what is true?

A Muslim will say that what is written in the Koran is the true word of God. No, no, says a Christian, the true word of God is revealed in the Bible. From their points of view, they are both right, and they are both wrong. Their truth is tied to their beliefs; if they believe something to be true, then it is.

“The truth . . . is a beautiful and terrible thing, and should therefore be treated with great caution.

— Professor Dumbledore in Harry Potter and the Sorcerer’s Son

Or, take how truth can change over time.

There are scientific laws. Those are true aren’t they? Perhaps.

Five hundred years ago science told us that the Sun rose in the east and set in the west. It did this every day; it never changed. And observers knew that the Sun was circling the Earth. This was obvious from its rising and setting.

Then, along came Nicolaus Copernicus. He said the scientists and religious leaders had it all wrong; the Sun didn’t move around the Earth, the Earth moved around the Sun. What had been true was now untrue. The truth itself did not change. What changed was our view of the truth.

But, how do we know the current truth won’t change over time? We don’t; after all earlier truths have been overturned by later knowledge. Perhaps, in the future, we will learn that everything we think we know about the Universe is an illusion.

Nicolaus Copernicus

Nicolaus Copernicus

The Brain in a Vat Problem

René Descartes (1596-1650) asked if the Universe might be the creation of what he called an “evil demon.” A more recent version of this idea is what’s known as the “brain in the vat” problem.

This suggests we are all part of a very elaborate simulation that creates our reality. Because the reality we experience is our only reality we cannot know for sure that we are not all brains in a vat.

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Then, another question pops up: is the civilization that is running the simulation also in it? The Internet Encyclopedia of Philosophy notes that “If you cannot now be sure that you are not a brain in a vat, then you cannot rule out the possibility that all of your beliefs about the external world are false.”

Tangled knots of riddles such as the brain-in-the-vat problem are called thought experiments. Philosophers use them to test our theories about truth, knowledge, reality, and consciousness.

“I believe in everything until it’s disproved. So I believe in fairies, the myths, dragons. It all exists, even if it’s in your mind. Who’s to say that dreams and nightmares aren’t as real as the here and now?

— John Lennon

Truth Theories

It would be nice if there was a single, simple theory about how to reach the truth, but this is philosophy, so there isn’t.

The correspondence theory seems easy to understand―on the surface. It says that something is true if it corresponds to known facts. So, “Grass is green” is a true statement. But, what if you live on the Arctic tundra or the Sahara Desert? Is grass green if you’ve never seen it?

The pragmatic theory of truth says that a belief is true if it has a useful application to daily life. This idea was promoted by William James (1842-1910), and it has its critics. It is useful to believe your best friend can be trusted, but is it true? Isn’t it possible that in some extreme circumstance your best friend will betray you? It happens.

And, Friedrich Nietzsche (1844-1900) pointed out that an untruth can be useful. Somebody facing charges in court might find a better outcome by lying.

According to the coherence theory of truth “a statement is true if it is logically consistent with other beliefs that are held to be true. A belief is false if it is inconsistent with (contradicts) other beliefs that are held to be true.” (West Valley College, California.)

“Men occasionally stumble over the truth, but most of them pick themselves up and hurry off as if nothing ever happened.

— Winston Churchill

Truth Filters

For most of us truth is influenced by beliefs, which come from how we were raised and the experiences we’ve had. So, people who are supposed to trade in truth, such as journalists, filter their reporting through their own beliefs. They may not be aware, on a conscious level, that they are doing this.

The good ones try to set their biases aside in covering stories but even they get tripped up and get their reporting wrong. Most newspapers carry daily apologies that start out with “In yesterday’s paper we incorrectly reported that . . . ”

“No man has a good enough memory to be a successful liar.

— Abraham Lincoln

Sometimes, the inaccuracies are deliberate. Fox News and Newsmax in the United States are notorious for peddling false news.

Pundifact is an organization that checks the accuracy of statements made by political commentators, bloggers, columnists etc. In a check of Fox News coverage it found that statements were true or mostly true 37 percent of the time; false and mostly false 51 percent of the time. The “Pants on fire” category came up in nine percent of the Fox News statements.

Our courtrooms are places dedicated to the search for truth, but the number of wrongful convictions shows they don’t always find it.

The outcome of a trial may depend on many things that have nothing to do with provable facts―truth. The decision of a jury may rest on the persuasiveness of defence counsel. Jury members may not like the look of the accused and base their verdict on that.

Lying by Telling a Truth

A common technique used by people who don’t want to flat-out lie is to tell a truth that is intended to deceive; it’s called paltering.

Mom: “Have you done your homework?”

Teen: “I’ve written an essay on The Merchant of Venice.”

Technically, the statement may be true, but it doesn’t answer the question. However, it leaves the impression that homework is being done.

“The truth will set you free, but first it will piss you off.

— Joe Klaas

When running for president, Donald Trump was questioned about allegations his company refused to rent apartments to African-Americans. There was a lawsuit that Mr. Trump said was settled with “no admission of guilt.” That’s true, but a New York Times investigation revealed that the Trump company routinely refused to rent apartments to Black people.

Paltering is a convenience used by advertisers, business executives, sales people, just about everybody.

Truth Without Support

During the administration of U.S. President George W. Bush (2001-2009) a lot of untruths were spoken. Expert evidence was ignored if it did not agree with the president’s policies. This denial of truth prompted talk show host Stephen Colbert to create the concept he called truthiness. Mr. Colbert defines the word as “the feeling that something is true, despite all evidence to the contrary.”

More recently, comedian Bill Maher has joined in with his “I don’t know it for a fact . . . I just know it’s true” routine. As with Mr. Colbert, this highlights the fact that lying by public officials is becoming more common.

In March 2017, former U.S. President Donald Trump accused his predecessor, Barack Obama, of wiretapping him. But, there is no evidence to support the accusation, nor many of the other statements he has made. Mr. Trump has taken the business of untruths to a new, very low level.

The Washington Post keeps a running log of the former president’s falsehoods. On leaving office the newspaper announced that Trump had told 30,573 falsehoods in four years. He has continued lying at a frantic pace as he falsely claims the election he lost was rigged against him.

Bonus Factoids

  • Cartesian skepticism is being doubtful about the truth of one’s beliefs. This philosophical concept was developed by René Descartes. He sat down (or he may have remained standing) to have a deep think about all his beliefs in an attempt to determine which ones were true. To do this requires a level of mental discipline few can achieve.
  • Truth drugs pop up in movies, spy novels, and elsewhere, but there’s no evidence they can force people to tell the truth.
  • The Oxford English Dictionary named its word of the year for 2016 as “post-truth.” (Small point of pickiness but that’s two words).

“Facts do not cease to exist because they are ignored."

— Aldous Huxley


  • “Philosophy.” West Valley College, October 16, 2017.
  • “Truth” Stanford Encyclopedia of Philosophy, January 22, 2013.
  • “What is Truth?” Paul Pardi, Philosophy News, January 29, 2015.
  • “FOX’s file.” Punditfact, undated.
  • “The Devious Art of Lying by Telling the Truth.” Melissa Hogenboom, BBC News, November 15, 2017.
  • “President Trump Has Made 1,628 False or Misleading Claims Over 298 Days.” Glenn Kessler et al., Washington Post, November 14, 2017.
  • “Donald Trump Didn't Tell the Truth 83 Times in 1 Day.” Chris Cillizza, CNN, November 2, 2018.

This content is accurate and true to the best of the author’s knowledge and is not meant to substitute for formal and individualized advice from a qualified professional.

© 2017 Rupert Taylor


Alhazen on March 09, 2018:

The article seems to conflate two different meanings of truth; the meaning of truth as discussed in philosophy and conventional truth as used ordinarily to mean the opposite of a lie. In my comment I shall just stick to the philosophical meaning and as used by scientists.

Something is true if it can be ascertained or shown to exist. And how do we do that? We do it by providing material and rational evidence that it exists.

But when we ask; what does it mean to exist? We discover that existence means having evidence. We thus conclude that truth (that is acceptable to everyone) is material and rational evidence. Individual beliefs of truth arising from personal experience due to beliefs or revelations or unusual events and encounters is just personal truth that is not experienced by everyone.

Kari Poulsen from Ohio on November 18, 2017:

This is a very nice look at what makes something true and the different ways people use to get around it. And I learned a new word, paltering. :)

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